Abstract: The sealing surfaces of steel pipe flange at various positions in petrochemical production site are exposed to corrosive medium for a long time, so there will be erosion pits of varying degrees. In the process of equipment maintenance, disassembly and reassembly, the flange sealing surface will be damaged if not protected in time. Light knife repair technology for the sealing surface of steel pipe flange can solve the above problems and provide technical support for long-term safe and stable operation of petrochemical production equipment. Based on the overhaul experience of petrochemical production units over the years, seven types of light knife repair technology for the sealing surface of steel pipe flange are classified into two categories. Combining with practical operation, this paper introduces these technologies, which provides reference for the repair of flange sealing surface.

Key words: steel pipe flange, sealing surface, light knife repair technology, application